<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /* 伪类选择器 :hover :focus */
        /* 鼠标滑过，适用所有标签 */
        a:hover {
            color: red;
        }

        textarea,
        input {
            /* 去掉轮廓线:表单标签默认带有轮廓线，所以通常使用都想要先清除outline */
            outline: none;
        }

        /* 获取焦点 */
        textarea:focus,
        input:focus {
            border: 2px solid red;
        }

        /* 属性选择器 [] */
        input[name=pwd] {
            background-color: aqua;
        }

        div[title="abc"] {
            color: red;
        }
    </style>
</head>

<body>
    <div title="abc">盒子</div>
    <a href="#">百度一下，你就知道了</a>
    <textarea name="" id="" cols="30" rows="10">内容</textarea>
    <input type="text" name="" id="" value="sss">
    <input type="password" name="pwd" id="" value="sss">
</body>

</html>